public class Application{
     	public static void main(String args[]){
      		Pillar pillar;
      		Geometry bottom =null;
     		pillar =new Pillar (bottom,100);  //null底的柱体
     		System.out.println("体积"+pillar.getVolume());
     		bottom=new Rectangle(12,22);
	    	pillar =new Pillar (bottom,58);  //pillar是具有矩形底的柱体
     		System.out.println("体积"+pillar.getVolume());
      		bottom=new Circle(10);
    		pillar =new Pillar (bottom,58); //pillar是具有圆形底的柱体
     		System.out.println("体积"+pillar.getVolume());
 	}
} 
